Fuse - Slow Burn?

[ShooterMcGavin]

I fused together my entire show like many times before. I always place white masking tape over it for protection. It was not raining but very humid. I pulled my trailer out of the garage maybe 3 hours ahead of time. I noticed after it had been out a while some of the tape was releasing and coming off of the fuse. I assume heat and humidity. I used visco, perfect fuse, and quick fuse. All seemed to burn much slower. I had to relight it a few times because the tape would burn and almost seem to melt the fuse underneath. Any ideas or suggestion? I finally got it all shot but it should have been seamless. I was disappointed and frustrated! Thank you!

[barehm]

you said you are placing white masking tape over it for protection - is that the sole way you're putting fuses together?

[ShooterMcGavin]

No, I am double zip tying every connection. I had 4 shots where the fuse burned in half at the connection. Never had that occur before. It seems that the fuse almost smoldered. It was new in the package and kept in my house up to the time I used it. I used maybe 10 packages so it has to be something that occurred after assembly. I don't know if the tape smothered the fuse or it was all just damp? I am stumped. Thank you for any input you may have.

[ShooterMcGavin]

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Photo for reference

[Fox One]

I've honestly never seen that happen before, but it is something I've always worried about as being a possibility. I likewise try to keep all exposed fuse covered for spark protection as well as to keep the dew from getting the fuse too moist. While perhaps what you experienced is just a problem associated with that particular brand of tape, it makes me consider alternative ways of protecting fuse, i.e., using aluminum foil or other materials.

[Engineer Cat]

I personally have never had any issues with Daves magic tape so I solely use that. I use zip ties in some areas but not over the tops of tubes. I have this fear of a zip tie head lodging in the side of a shell and it not existing the tube so i just use the magic tape for that. And it sticks to everything. Even with some dampness around. Burns right through the tape.

[gecko2015]

No, I am double zip tying every connection. I had 4 shots where the fuse burned in half at the connection. Never had that occur before. It seems that the fuse almost smoldered. It was new in the package and kept in my house up to the time I used it. I used maybe 10 packages so it has to be something that occurred after assembly. I don't know if the tape smothered the fuse or it was all just damp? I am stumped. Thank you for any input you may have.

I've heard and seen that sometimes the zip-ties can pinch the fuse just enough to stop the flame. Were all the stops of the fuse flame at or very near the zip connection?

If so, I'd be more inclined to suspect the zips to be the cause and not the fuse or tape.

[Kooooou]

I never used masking tape for fireworks purposes, but I stopped using Scotch clear tape a long time ago because my fuse connections were exhibiting the same thing you saw, which to me looked like a smother or slow burnout of a main fuse. I can't say that was actually what happened, but it happened enough times to make me stop using any tape on fuses. When I have to fuse items together now, such as a rack or multiple cakes on one fuse, I zip tie twice per connection and use foil to protect the fuse from stray sparks. Once in a blue moon, I will use tape to quickly upright a sagging fuse but I make sure the tape is very loosely touching the fuse.

[ShooterMcGavin]

Most stops were at the zip ties however, this was just 4 out of over 250 connections. The real issue was the fuse burning really slow. I measured every connection so that the next cake would be starting exactly when the one before finished but sometime it would be more than a minute just smoldering while the tape burned. Thank you for the input!

[Kooooou]

I've heard and seen that sometimes the zip-ties can pinch the fuse just enough to stop the flame. Were all the stops of the fuse flame at or very near the zip connection?

If so, I'd be more inclined to suspect the zips to be the cause and not the fuse or tape.
I agree with you on zip ties pinching fuses and it happens. For that reason, I use the smallest zip ties possible for the job which is usually 4" long, and then tighten them just enough to allow full contact between visco. Seems to eliminate the zip tie problems.

[Arles]

Most stops were at the zip ties however, this was just 4 out of over 250 connections. The real issue was the fuse burning really slow. I measured every connection so that the next cake would be starting exactly when the one before finished but sometime it would be more than a minute just smoldering while the tape burned. Thank you for the input!

Sounds like a bad batch of fuse to me that was either defective from the manufacturer or tainted along the way.

[gecko2015]

Most stops were at the zip ties however, this was just 4 out of over 250 connections. The real issue was the fuse burning really slow. I measured every connection so that the next cake would be starting exactly when the one before finished but sometime it would be more than a minute just smoldering while the tape burned. Thank you for the input!

Only other cause I can think of would be the masking tape. Masking tape typically has more of a 'papery' material than other tapes; making it more absorbent than other tapes. Meaning, it might've been soaking up all that humidity and then transferring that moisture to the fuse's protective coating. That might explain the slower burning fuse and why it was failing to stick to the the fuse (being the moisture was penetrating the exterior of the tape and made it's way through to the sticky side making the adhesive less effective).

One of the best tips Dave has ever given is that damn magic tape. I've used it every single year and it is the absolute best tape to work with with fireworks. I always go out my way to ensure I've got a few rolls on hand when doing my shows.

My show was also very humid this year; so much so, I was worried it was going to damage the electronics in my Cobra controller, modules, or my laptop as they were soaking wet on their exteriors. But all the tape I used to cover my fuses like you do were still doing their job and none had to be reapplied. I didn't have any fuse failures.

If I were a guessing man and was in your shoes, I'd probably suspect the tape to be the main culprit all things considered.

[barehm]

two thoughts:

1) I've had the same fuse product burn different speeds. In other words, Green Visco, even from the same manufacturer, will often vary in speeds. I think some websites even warn this. I've had good luck with all the visco in a single case burning the same, but not between cases. I test if I care. Not a slam dunk, but how slow are we talking? was it 90 seconds a foot? longer?

2) I got a zip tie gun and tested ratcheting down fuse with various tension settings. It's not easy to snuff the fuse, but if I set my gun to 3, I can do it pretty consistently. At 1, I never got it to fail. I'm leaning towards fewer and fewer zip ties the more I watch the hold of the u-haul tape. It doesn't seem like it's gripping that much because it's so easy to work with, but god help you if you need to take it apart later - you'll need a razor blade. I might use no zip ties next year - I have no evidence it's actually holding fuses together any better than the tape alone. It feels safer to me, but that's a pretty crappy scientific approach :).

[N.E. Pyrotechnics]

When we first got started, way back in 2019 we tried using wire ties. Lots of mixed results, but if I tried, I could make the pass fire fail every time just by over-tightening the wire tie. We switched to 1" masking tape, and that is all we use now. I have had boards, and shell chains put together a week in advance of shooting without any tape failures. Product was stored in a non-climate controlled environment, during a Michigan summer. I was most concerned with humidity levels, but it has not been an issue for us yet...